STRLCPY/dnstt

Merge tag 'v0.20210424.0' into plugin
```
tag v0.20210424.0
```
Mygod committed 3 years ago

f96fe00a

2 parents
966c0c15
169a43e6

Revision indexing in progress... (symbol navigation in revisions will be accurate after indexed)

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CHANGELOG

	1	+	## v0.20210424.0
	2	+
	3	+	dnstt was part of a software security audit done by Cure53. The report
	4	+	found issues of severity levels Low–Medium in dnstt and in one of its
	5	+	dependencies, a package used for Noise cryptography. This release fixes
	6	+	the following issues:
	7	+	* UCB-02-002: Memory leak in acceptStreams() routine of dnstt server (Low)
	8	+	* UCB-02-003: Potential nonce overflow in Noise protocol (Medium)
	9	+	* UCB-02-004: Deprecated DH25519 Golang API used by Noise (Low)
	10	+	* UCB-02-006: DoS due to unconditional nonce increment (Low)
	11	+	* UCB-02-007: DoS due to missing socket timeouts (Low)
	12	+	Unaddressed in this release are:
	13	+	* UCB-02-005: Client ID security considerations & Noise authenticated data (Low)
	14	+	* UCB-02-008: Lack of rate limiting in Snowflake and dnstt (Info)
	15	+	Two other issues in the report, UCB-02-001 and UCB-02-009, do not have
	16	+	to do with dnstt. For more details and the text of the report, see
	17	+	https://www.bamsoftware.com/software/dnstt/security.html#cure53-turbotunnel-2021
	18	+
	19	+	Added man pages for dnstt-client and dnstt-server.
	20	+
	21	+
	22	+	## v0.20200506.0
	23	+
	24	+	Documentation updates.
	25	+
	26	+
1	27		## v0.20200504.0
2	28
3	29		Documentation updates and link to web page.
		skipped 33 lines

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README

		skipped 196 lines
197	197		```
198	198		tunnel-client$ ./dnstt-client -doh https://doh.example/dns-query -pubkey-file server.pub t.example.com 127.0.0.1:2222
199	199		tunnel-client$ ssh -v -N -D 127.0.0.1:7000 -o HostKeyAlias=tunnel-server -p 2222 127.0.0.1
200		-	tunnel-client$ curl --proxy http://127.0.0.1:7000/ https://wtfismyip.com/text
	200	+	tunnel-client$ curl --proxy socks5h://127.0.0.1:7000/ https://wtfismyip.com/text
201	201		```
202	202
203	203
		skipped 143 lines

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dns/dns.go

		skipped 100 lines
101	101		} else {
102	102		return NewName(bytes.Split(b, []byte(".")))
103	103		}
104		-	return NewName(bytes.Split(b, []byte(".")))
105	104		}
106	105
107	106		// String returns a string representation of name, with labels separated by
		skipped 71 lines
179	178		}
180	179
181	180		// readName parses a DNS name from r. It leaves r positioned just after the
182		-	// parsed named.
	181	+	// parsed name.
183	182		func readName(r io.ReadSeeker) (Name, error) {
184	183		var labels [][]byte
185	184		// We limit the number of compression pointers we are willing to follow.
		skipped 372 lines

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dns/dns_test.go

		skipped 37 lines
38	38		{[][]byte{[]byte("test")}, nil, "test"},
39	39		{[][]byte{[]byte("a"), []byte("b"), []byte("c")}, nil, "a.b.c"},
40	40
41		-	{[][]byte{[]byte{}}, ErrZeroLengthLabel, ""},
42		-	{[][]byte{[]byte("a"), []byte{}, []byte("c")}, ErrZeroLengthLabel, ""},
	41	+	{[][]byte{{}}, ErrZeroLengthLabel, ""},
	42	+	{[][]byte{[]byte("a"), {}, []byte("c")}, ErrZeroLengthLabel, ""},
43	43
44	44		// 63 octets.
45	45		{[][]byte{[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE")}, nil,
		skipped 213 lines
259	259		// EOF while reading label.
260	260		{0, "\x0aexample", io.ErrUnexpectedEOF},
261	261		// EOF before second byte of pointer.
	262	+	{0, "\xc0", io.ErrUnexpectedEOF},
262	263		{0, "\x07example\xc0", io.ErrUnexpectedEOF},
263	264		} {
264	265		r := bytes.NewReader([]byte(test.input))
		skipped 144 lines
409	410
410	411		func TestMessageWireFormatRoundTrip(t *testing.T) {
411	412		for _, message := range []Message{
412		-	Message{
	413	+	{
413	414		ID: 0x1234,
414	415		Flags: 0x0100,
415	416		Question: []Question{
		skipped 84 lines
500	501		// 255 bytes should be able to be encoded into 256 bytes.
501	502		p = make([]byte, 255)
502	503		encoded = EncodeRDataTXT(p)
503		-	t.Errorf("%x", encoded)
504	504		if len(encoded) > 256 {
505	505		t.Errorf("EncodeRDataTXT(%d bytes) returned %d bytes", len(p), len(encoded))
506	506		}
		skipped 1 lines
508	508
509	509		func TestRDataTXTRoundTrip(t *testing.T) {
510	510		for _, p := range [][]byte{
511		-	[]byte{},
	511	+	{},
512	512		[]byte("\x00"),
513	513		{
514	514		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
		skipped 26 lines

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dns/fuzz.go

1	+	// +build gofuzz
2	+
3	+	// Fuzzing driver for https://github.com/dvyukov/go-fuzz.
4	+	// go get -u github.com/dvyukov/go-fuzz/go-fuzz github.com/dvyukov/go-fuzz/go-fuzz-build
5	+	// $GOPATH/bin/go-fuzz-build
6	+	// $GOPATH/bin/go-fuzz
7	+	//
8	+	// Related link: https://blog.cloudflare.com/dns-parser-meet-go-fuzzer/
9	+
10	+	package dns
11	+
12	+	func Fuzz(data []byte) int {
13	+	msg, err := MessageFromWireFormat(data)
14	+	if err != nil {
15	+	return 0
16	+	}
17	+	_, err = msg.WireFormat()
18	+	if err != nil {
19	+	panic(err)
20	+	}
21	+	return 1 // prioritize this input
22	+	}
23	+

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dnstt-client/dns.go

		skipped 306 lines
307	307		{
308	308		Name: dns.Name{},
309	309		Type: dns.RRTypeOPT,
310		-	Class: 4096, // requestor's UDP payload size
	310	+	Class: 4096, // requester's UDP payload size
311	311		TTL: 0, // extended RCODE and flags
312	312		Data: []byte{},
313	313		},
		skipped 74 lines

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dnstt-client/http.go

		skipped 25 lines
26	26		// HTTPS (DoH). Its WriteTo and ReadFrom methods exchange DNS messages over HTTP
27	27		// requests and responses.
28	28		//
29		-	// HTTPPacketConn deals only with alreaday formatted DNS messages. It does not
	29	+	// HTTPPacketConn deals only with already formatted DNS messages. It does not
30	30		// handle encoding information into the messages. That is rather the
31	31		// responsibility of DNSPacketConn.
32	32		//
		skipped 65 lines
98	98		default:
99	99		// We primarily are thinking of 429 Too Many Requests here, but
100	100		// any other unexpected response codes will also cause us to
101		-	// rate-limit ourself and emit a log message.
	101	+	// rate-limit ourselves and emit a log message.
102	102		// https://developers.google.com/speed/public-dns/docs/doh/#errors
103	103		now := time.Now()
104	104		var retryAfter time.Time
		skipped 67 lines

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dnstt-client/main.go

		skipped 95 lines
96	96		err = nil
97	97		}
98	98		if err != nil {
99		-	log.Printf("stream %08x:%d copy stream←local: %v\n", conv, stream.ID(), err)
	99	+	log.Printf("stream %08x:%d copy stream←local: %v", conv, stream.ID(), err)
100	100		}
101	101		local.CloseRead()
102	102		stream.Close()
		skipped 6 lines
109	109		err = nil
110	110		}
111	111		if err != nil && err != io.ErrClosedPipe {
112		-	log.Printf("stream %08x:%d copy local←stream: %v\n", conv, stream.ID(), err)
	112	+	log.Printf("stream %08x:%d copy local←stream: %v", conv, stream.ID(), err)
113	113		}
114	114		local.CloseWrite()
115	115		}()
		skipped 15 lines
131	131		if mtu < 80 {
132	132		return fmt.Errorf("domain %s leaves only %d bytes for payload", domain, mtu)
133	133		}
134		-	log.Printf("effective MTU %d\n", mtu)
	134	+	log.Printf("effective MTU %d", mtu)
135	135
136	136		// Open a KCP conn on the PacketConn.
137	137		conn, err := kcp.NewConn2(remoteAddr, nil, 0, 0, pconn)
		skipped 7 lines
145	145		log.Printf("begin session %08x", conn.GetConv())
146	146		// Permit coalescing the payloads of consecutive sends.
147	147		conn.SetStreamMode(true)
148		-	// Disable the dynamic congestion window (limit only by the
149		-	// maximum of local and remote static windows).
	148	+	// Disable the dynamic congestion window (limit only by the maximum of
	149	+	// local and remote static windows).
150	150		conn.SetNoDelay(
151	151		0, // default nodelay
152	152		0, // default interval
		skipped 32 lines
185	185		defer local.Close()
186	186		err := handle(local.(*net.TCPConn), sess, conn.GetConv())
187	187		if err != nil {
188		-	log.Printf("handle: %v\n", err)
	188	+	log.Printf("handle: %v", err)
189	189		}
190	190		}()
191	191		}
		skipped 124 lines

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dnstt-client/tls.go

		skipped 7 lines
8	8		"log"
9	9		"net"
10	10		"sync"
	11	+	"time"
11	12
12	13		"www.bamsoftware.com/git/dnstt.git/turbotunnel"
13	14		)
	15	+
	16	+	const dialTimeout = 30 * time.Second
14	17
15	18		// TLSPacketConn is a TLS- and TCP-based transport for DNS messages, used for
16	19		// DNS over TLS (DoT). Its WriteTo and ReadFrom methods exchange DNS messages
17	20		// over a TLS channel, prefixing each message with a two-octet length field as
18	21		// in DNS over TCP.
19	22		//
20		-	// TLSPacketConn deals only with alreaday formatted DNS messages. It does not
	23	+	// TLSPacketConn deals only with already formatted DNS messages. It does not
21	24		// handle encoding information into the messages. That is rather the
22	25		// responsibility of DNSPacketConn.
23	26		//
		skipped 17 lines
41	44		// becomes disconnected. We do the first dial here, outside the
42	45		// goroutine, so that any immediate and permanent connection errors are
43	46		// reported directly to the caller of NewTLSPacketConn.
	47	+	dialer := &net.Dialer{
	48	+	Timeout: dialTimeout,
	49	+	}
44	50		tlsConfig := &tls.Config{}
45		-	conn, err := tls.Dial("tcp", addr, tlsConfig)
	51	+	conn, err := tls.DialWithDialer(dialer, "tcp", addr, tlsConfig)
46	52		if err != nil {
47	53		return nil, err
48	54		}
		skipped 20 lines
69	75		conn.Close()
70	76
71	77		// Whenever the TLS connection dies, redial a new one.
72		-	conn, err = tls.Dial("tcp", addr, tlsConfig)
	78	+	conn, err = tls.DialWithDialer(dialer, "tcp", addr, tlsConfig)
73	79		if err != nil {
74	80		log.Printf("tls.Dial: %v", err)
75	81		break
		skipped 53 lines

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dnstt-server/main.go

		skipped 5 lines
6	6		//
7	7		// Example:
8	8		// dnstt-server -gen-key -privkey-file server.key -pubkey-file server.pub
9		-	// dnstt-server -udp 127.0.0.1:5300 -privkey-file server.key t.example.com 127.0.0.1:8000
	9	+	// dnstt-server -udp :53 -privkey-file server.key t.example.com 127.0.0.1:8000
10	10		//
11	11		// To generate a persistent server private key, first run with the -gen-key
12	12		// option. By default the generated private and public keys are printed to
		skipped 10 lines
23	23		// queries.
24	24		//
25	25		// The -mtu option controls the maximum size of response UDP payloads.
26		-	// Queries that do not advertise requestor support for responses of at least
	26	+	// Queries that do not advertise requester support for responses of at least
27	27		// this size at least this size will be responded to with a FORMERR. The default
28	28		// value is maxUDPPayload.
29	29		//
		skipped 41 lines
71	71		// to be the query timeout of the Quad9 DoH server.
72	72		// https://dnsencryption.info/imc19-doe.html Section 4.2, Finding 2.4
73	73		maxResponseDelay = 1 * time.Second
	74	+
	75	+	// How long to wait for a TCP connection to upstream to be established.
	76	+	upstreamDialTimeout = 30 * time.Second
74	77		)
75	78
76	79		var (
		skipped 104 lines
181	184
182	185		// handleStream bidirectionally connects a client stream with a TCP socket
183	186		// addressed by upstream.
184		-	func handleStream(stream smux.Stream, upstream net.TCPAddr, conv uint32) error {
185		-	conn, err := net.DialTCP("tcp", nil, upstream)
	187	+	func handleStream(stream *smux.Stream, upstream string, conv uint32) error {
	188	+	dialer := net.Dialer{
	189	+	Timeout: upstreamDialTimeout,
	190	+	}
	191	+	upstreamConn, err := dialer.Dial("tcp", upstream)
186	192		if err != nil {
187	193		return fmt.Errorf("stream %08x:%d connect upstream: %v", conv, stream.ID(), err)
188	194		}
189		-	defer conn.Close()
	195	+	defer upstreamConn.Close()
	196	+	upstreamTCPConn := upstreamConn.(*net.TCPConn)
190	197
191	198		var wg sync.WaitGroup
192	199		wg.Add(2)
193	200		go func() {
194	201		defer wg.Done()
195		-	_, err := io.Copy(stream, conn)
	202	+	_, err := io.Copy(stream, upstreamTCPConn)
196	203		if err == io.EOF {
197	204		// smux Stream.Write may return io.EOF.
198	205		err = nil
199	206		}
200	207		if err != nil {
201		-	log.Printf("stream %08x:%d copy stream←upstream: %v\n", conv, stream.ID(), err)
	208	+	log.Printf("stream %08x:%d copy stream←upstream: %v", conv, stream.ID(), err)
202	209		}
203		-	conn.CloseRead()
	210	+	upstreamTCPConn.CloseRead()
204	211		stream.Close()
205	212		}()
206	213		go func() {
207	214		defer wg.Done()
208		-	_, err := io.Copy(conn, stream)
	215	+	_, err := io.Copy(upstreamTCPConn, stream)
209	216		if err == io.EOF {
210	217		// smux Stream.WriteTo may return io.EOF.
211	218		err = nil
212	219		}
213	220		if err != nil && err != io.ErrClosedPipe {
214		-	log.Printf("stream %08x:%d copy upstream←stream: %v\n", conv, stream.ID(), err)
	221	+	log.Printf("stream %08x:%d copy upstream←stream: %v", conv, stream.ID(), err)
215	222		}
216		-	conn.CloseWrite()
	223	+	upstreamTCPConn.CloseWrite()
217	224		}()
218	225		wg.Wait()
219	226
		skipped 2 lines
222	229
223	230		// acceptStreams wraps a KCP session in a Noise channel and an smux.Session,
224	231		// then awaits smux streams. It passes each stream to handleStream.
225		-	func acceptStreams(conn kcp.UDPSession, privkey, pubkey []byte, upstream net.TCPAddr) error {
	232	+	func acceptStreams(conn *kcp.UDPSession, privkey, pubkey []byte, upstream string) error {
226	233		// Put a Noise channel on top of the KCP conn.
227	234		rw, err := noise.NewServer(conn, privkey, pubkey)
228	235		if err != nil {
		skipped 8 lines
237	244		if err != nil {
238	245		return err
239	246		}
	247	+	defer sess.Close()
240	248
241	249		for {
242	250		stream, err := sess.AcceptStream()
		skipped 11 lines
254	262		}()
255	263		err := handleStream(stream, upstream, conn.GetConv())
256	264		if err != nil {
257		-	log.Printf("stream %08x:%d handleStream: %v\n", conn.GetConv(), stream.ID(), err)
	265	+	log.Printf("stream %08x:%d handleStream: %v", conn.GetConv(), stream.ID(), err)
258	266		}
259	267		}()
260	268		}
		skipped 1 lines
262	270
263	271		// acceptSessions listens for incoming KCP connections and passes them to
264	272		// acceptStreams.
265		-	func acceptSessions(ln kcp.Listener, privkey, pubkey []byte, mtu int, upstream net.TCPAddr) error {
	273	+	func acceptSessions(ln *kcp.Listener, privkey, pubkey []byte, mtu int, upstream string) error {
266	274		for {
267	275		conn, err := ln.AcceptKCP()
268	276		if err != nil {
		skipped 23 lines
292	300		}()
293	301		err := acceptStreams(conn, privkey, pubkey, upstream)
294	302		if err != nil {
295		-	log.Printf("session %08x acceptStreams: %v\n", conn.GetConv(), err)
	303	+	log.Printf("session %08x acceptStreams: %v", conn.GetConv(), err)
296	304		}
297	305		}()
298	306		}
		skipped 54 lines
353	361		}
354	362
355	363		// Check for EDNS(0) support. Include our own OPT RR only if we receive
356		-	// one from the requestor.
	364	+	// one from the requester.
357	365		// https://tools.ietf.org/html/rfc6891#section-6.1.1
358	366		// "Lack of presence of an OPT record in a request MUST be taken as an
359		-	// indication that the requestor does not implement any part of this
	367	+	// indication that the requester does not implement any part of this
360	368		// specification and that the responder MUST NOT include an OPT record
361	369		// in its response."
362	370		payloadSize := 0
		skipped 43 lines
406	414		// There must be exactly one question.
407	415		if len(query.Question) != 1 {
408	416		resp.Flags \|= dns.RcodeFormatError
409		-	log.Printf("FORMERR: too many questions (%d)", len(query.Question))
	417	+	log.Printf("FORMERR: too few or too many questions (%d)", len(query.Question))
410	418		return resp, nil
411	419		}
412	420		question := query.Question[0]
		skipped 47 lines
460	468		// FORMERR MUST be returned."
461	469		if payloadSize < maxUDPPayload {
462	470		resp.Flags \|= dns.RcodeFormatError
463		-	log.Printf("FORMERR: requestor payload size %d is too small (minimum %d)", payloadSize, maxUDPPayload)
	471	+	log.Printf("FORMERR: requester payload size %d is too small (minimum %d)", payloadSize, maxUDPPayload)
464	472		return resp, nil
465	473		}
466	474
		skipped 232 lines
699	707		{
700	708		Name: dns.Name{},
701	709		Type: dns.RRTypeOPT,
702		-	Class: queryLimit, // requestor's UDP payload size
	710	+	Class: queryLimit, // requester's UDP payload size
703	711		TTL: 0, // extended RCODE and flags
704	712		Data: []byte{},
705	713		},
		skipped 32 lines
738	746		return low
739	747		}
740	748
741		-	func run(privkey, pubkey []byte, domain dns.Name, upstream net.Addr, dnsConn net.PacketConn) error {
	749	+	func run(privkey, pubkey []byte, domain dns.Name, upstream string, dnsConn net.PacketConn) error {
742	750		defer dnsConn.Close()
743	751
744	752		log.Printf("pubkey %x", pubkey)
		skipped 14 lines
759	767		}
760	768		return fmt.Errorf("maximum UDP payload size of %d leaves only %d bytes for payload", maxUDPPayload, mtu)
761	769		}
762		-	log.Printf("effective MTU %d\n", mtu)
	770	+	log.Printf("effective MTU %d", mtu)
763	771
764	772		// Start up the virtual PacketConn for turbotunnel.
765	773		ttConn := turbotunnel.NewQueuePacketConn(turbotunnel.DummyAddr{}, idleTimeout*2)
		skipped 3 lines
769	777		}
770	778		defer ln.Close()
771	779		go func() {
772		-	err := acceptSessions(ln, privkey, pubkey, mtu, upstream.(*net.TCPAddr))
	780	+	err := acceptSessions(ln, privkey, pubkey, mtu, upstream)
773	781		if err != nil {
774		-	log.Printf("acceptSessions: %v\n", err)
	782	+	log.Printf("acceptSessions: %v", err)
775	783		}
776	784		}()
777	785
		skipped 27 lines
805	813
806	814		Example:
807	815		%[1]s -gen-key -privkey-file server.key -pubkey-file server.pub
808		-	%[1]s -udp 127.0.0.1:5300 -privkey-file server.key t.example.com 127.0.0.1:8000
	816	+	%[1]s -udp :53 -privkey-file server.key t.example.com 127.0.0.1:8000
809	817
810	818		`, os.Args[0])
811	819		flag.PrintDefaults()
		skipped 29 lines
841	849		fmt.Fprintf(os.Stderr, "invalid domain %+q: %v\n", flag.Arg(0), err)
842	850		os.Exit(1)
843	851		}
844		-	upstream, err := net.ResolveTCPAddr("tcp", flag.Arg(1))
845		-	if err != nil {
846		-	fmt.Fprintf(os.Stderr, "cannot resolve %+q: %v\n", flag.Arg(1), err)
847		-	os.Exit(1)
	852	+	upstream := flag.Arg(1)
	853	+	// We keep upstream as a string in order to eventually pass it
	854	+	// to net.Dial in handleStream. But for the sake of displaying
	855	+	// an error or warning at startup, rather than only when the
	856	+	// first stream occurs, we apply some parsing and name
	857	+	// resolution checks here.
	858	+	{
	859	+	upstreamHost, _, err := net.SplitHostPort(upstream)
	860	+	if err != nil {
	861	+	// host:port format is required in all cases, so
	862	+	// this is a fatal error.
	863	+	fmt.Fprintf(os.Stderr, "cannot parse upstream address %+q: %v\n", upstream, err)
	864	+	os.Exit(1)
	865	+	}
	866	+	upstreamIPAddr, err := net.ResolveIPAddr("ip", upstreamHost)
	867	+	if err != nil {
	868	+	// Failure to resolve the host portion is only a
	869	+	// warning. The name will be re-resolved on each
	870	+	// net.Dial in handleStream.
	871	+	log.Printf("warning: cannot resolve upstream host %+q: %v", upstreamHost, err)
	872	+	} else if upstreamIPAddr.IP == nil {
	873	+	// Handle the special case of an empty string
	874	+	// for the host portion, which resolves to a nil
	875	+	// IP. This is a fatal error as we will not be
	876	+	// able to dial this address.
	877	+	fmt.Fprintf(os.Stderr, "cannot parse upstream address %+q: missing host in address\n", upstream)
	878	+	os.Exit(1)
	879	+	}
848	880		}
849	881
850	882		if udpAddr == "" {
		skipped 52 lines

■ ■ ■ ■ ■ ■

go.mod

1	1		module www.bamsoftware.com/git/dnstt.git
2	2
	3	+	go 1.11
	4	+
3	5		require (
4		-	github.com/flynn/noise v0.0.0-20180327030543-2492fe189ae6
5		-	github.com/xtaci/kcp-go/v5 v5.5.12
6		-	github.com/xtaci/smux v1.5.12
	6	+	github.com/flynn/noise v1.0.0
	7	+	github.com/xtaci/kcp-go/v5 v5.6.1
	8	+	github.com/xtaci/smux v1.5.15
7	9		)
8	10

■ ■ ■ ■ ■ ■

go.sum

1		-	github.com/flynn/noise v0.0.0-20180327030543-2492fe189ae6 h1:u/UEqS66A5ckRmS4yNpjmVH56sVtS/RfclBAYocb4as=
2		-	github.com/flynn/noise v0.0.0-20180327030543-2492fe189ae6/go.mod h1:1i71OnUq3iUe1ma7Lr6yG6/rjvM3emb6yoL7xLFzcVQ=
3		-	github.com/klauspost/cpuid v1.2.2 h1:1xAgYebNnsb9LKCdLOvFWtAxGU/33mjJtyOVbmUa0Us=
4		-	github.com/klauspost/cpuid v1.2.2/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
5		-	github.com/klauspost/reedsolomon v1.9.3 h1:N/VzgeMfHmLc+KHMD1UL/tNkfXAt8FnUqlgXGIduwAY=
6		-	github.com/klauspost/reedsolomon v1.9.3/go.mod h1:CwCi+NUr9pqSVktrkN+Ondf06rkhYZ/pcNv7fu+8Un4=
7		-	github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
8		-	github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
	1	+	github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
	2	+	github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
	3	+	github.com/flynn/noise v1.0.0 h1:DlTHqmzmvcEiKj+4RYo/imoswx/4r6iBlCMfVtrMXpQ=
	4	+	github.com/flynn/noise v1.0.0/go.mod h1:xbMo+0i6+IGbYdJhF31t2eR1BIU0CYc12+BNAKwUTag=
	5	+	github.com/klauspost/cpuid v1.2.4/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
	6	+	github.com/klauspost/cpuid v1.3.1 h1:5JNjFYYQrZeKRJ0734q51WCEEn2huer72Dc7K+R/b6s=
	7	+	github.com/klauspost/cpuid v1.3.1/go.mod h1:bYW4mA6ZgKPob1/Dlai2LviZJO7KGI3uoWLd42rAQw4=
	8	+	github.com/klauspost/reedsolomon v1.9.9 h1:qCL7LZlv17xMixl55nq2/Oa1Y86nfO8EqDfv2GHND54=
	9	+	github.com/klauspost/reedsolomon v1.9.9/go.mod h1:O7yFFHiQwDR6b2t63KPUpccPtNdp5ADgh1gg4fd12wo=
	10	+	github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
	11	+	github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
	12	+	github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
	13	+	github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
	14	+	github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
	15	+	github.com/mmcloughlin/avo v0.0.0-20200803215136-443f81d77104 h1:ULR/QWMgcgRiZLUjSSJMU+fW+RDMstRdmnDWj9Q+AsA=
	16	+	github.com/mmcloughlin/avo v0.0.0-20200803215136-443f81d77104/go.mod h1:wqKykBG2QzQDJEzvRkcS8x6MiSJkF52hXZsXcjaB3ls=
	17	+	github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
	18	+	github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
	19	+	github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
	20	+	github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
	21	+	github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
	22	+	github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
	23	+	github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
9	24		github.com/templexxx/cpu v0.0.1 h1:hY4WdLOgKdc8y13EYklu9OUTXik80BkxHoWvTO6MQQY=
10	25		github.com/templexxx/cpu v0.0.1/go.mod h1:w7Tb+7qgcAlIyX4NhLuDKt78AHA5SzPmq0Wj6HiEnnk=
	26	+	github.com/templexxx/cpu v0.0.7 h1:pUEZn8JBy/w5yzdYWgx+0m0xL9uk6j4K91C5kOViAzo=
	27	+	github.com/templexxx/cpu v0.0.7/go.mod h1:w7Tb+7qgcAlIyX4NhLuDKt78AHA5SzPmq0Wj6HiEnnk=
11	28		github.com/templexxx/xorsimd v0.4.1 h1:iUZcywbOYDRAZUasAs2eSCUW8eobuZDy0I9FJiORkVg=
12	29		github.com/templexxx/xorsimd v0.4.1/go.mod h1:W+ffZz8jJMH2SXwuKu9WhygqBMbFnp14G2fqEr8qaNo=
13		-	github.com/tjfoc/gmsm v1.0.1 h1:R11HlqhXkDospckjZEihx9SW/2VW0RgdwrykyWMFOQU=
14		-	github.com/tjfoc/gmsm v1.0.1/go.mod h1:XxO4hdhhrzAd+G4CjDqaOkd0hUzmtPR/d3EiBBMn/wc=
15		-	github.com/xtaci/kcp-go/v5 v5.5.12 h1:iALGyvti/oBbl1TbVoUpHEUHCorDEb3tEKl1CPY3KXM=
16		-	github.com/xtaci/kcp-go/v5 v5.5.12/go.mod h1:H0T/EJ+lPNytnFYsKLH0JHUtiwZjG3KXlTM6c+Q4YUo=
	30	+	github.com/tjfoc/gmsm v1.3.2 h1:7JVkAn5bvUJ7HtU08iW6UiD+UTmJTIToHCfeFzkcCxM=
	31	+	github.com/tjfoc/gmsm v1.3.2/go.mod h1:HaUcFuY0auTiaHB9MHFGCPx5IaLhTUd2atbCFBQXn9w=
	32	+	github.com/xtaci/kcp-go/v5 v5.6.1 h1:Pwn0aoeNSPF9dTS7IgiPXn0HEtaIlVb6y5UKWPsx8bI=
	33	+	github.com/xtaci/kcp-go/v5 v5.6.1/go.mod h1:W3kVPyNYwZ06p79dNwFWQOVFrdcBpDBsdyvK8moQrYo=
	34	+	github.com/xtaci/lossyconn v0.0.0-20190602105132-8df528c0c9ae h1:J0GxkO96kL4WF+AIT3M4mfUVinOCPgf2uUWYFUzN0sM=
17	35		github.com/xtaci/lossyconn v0.0.0-20190602105132-8df528c0c9ae/go.mod h1:gXtu8J62kEgmN++bm9BVICuT/e8yiLI2KFobd/TRFsE=
18		-	github.com/xtaci/smux v1.5.12 h1:n9OGjdqQuVZXLh46+L4IR5tR2wvuUFwRABnN/V55bIY=
19		-	github.com/xtaci/smux v1.5.12/go.mod h1:OMlQbT5vcgl2gb49mFkYo6SMf+zP3rcjcwQz7ZU7IGY=
	36	+	github.com/xtaci/smux v1.5.15 h1:6hMiXswcleXj5oNfcJc+DXS8Vj36XX2LaX98udog6Kc=
	37	+	github.com/xtaci/smux v1.5.15/go.mod h1:OMlQbT5vcgl2gb49mFkYo6SMf+zP3rcjcwQz7ZU7IGY=
	38	+	github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
	39	+	github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
	40	+	golang.org/x/arch v0.0.0-20190909030613-46d78d1859ac/go.mod h1:flIaEI6LNU6xOCD5PaJvn9wGP0agmIOqjrtsKGRguv4=
20	41		golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
21		-	golang.org/x/crypto v0.0.0-20191206172530-e9b2fee46413 h1:ULYEB3JvPRE/IfO+9uO7vKV/xzVTO7XPAwm8xbf4w2g=
22		-	golang.org/x/crypto v0.0.0-20191206172530-e9b2fee46413/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
	42	+	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
	43	+	golang.org/x/crypto v0.0.0-20191219195013-becbf705a915/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
	44	+	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
	45	+	golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
	46	+	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2 h1:It14KIkyBFYkHkwZ7k45minvA9aorojkyjGk9KJ5B/w=
	47	+	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
	48	+	golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
	49	+	golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
	50	+	golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
23	51		golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
24		-	golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553 h1:efeOvDhwQ29Dj3SdAV/MJf8oukgn+8D8WgaCaRMchF8=
25		-	golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
	52	+	golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
	53	+	golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
	54	+	golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
	55	+	golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
	56	+	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 h1:qWPm9rbaAMKs8Bq/9LRpbMqxWRVUAQwMI9fVrssnTfw=
	57	+	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
	58	+	golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
	59	+	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
	60	+	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
26	61		golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
27	62		golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
28		-	golang.org/x/sys v0.0.0-20191228213918-04cbcbbfeed8 h1:JA8d3MPx/IToSyXZG/RhwYEtfrKO1Fxrqe8KrkiLXKM=
29		-	golang.org/x/sys v0.0.0-20191228213918-04cbcbbfeed8/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
	63	+	golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
	64	+	golang.org/x/sys v0.0.0-20200808120158-1030fc2bf1d9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
	65	+	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
	66	+	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
	67	+	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
30	68		golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
	69	+	golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
	70	+	golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
	71	+	golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
	72	+	golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
	73	+	golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123 h1:4JSJPND/+4555t1HfXYF4UEqDqiSKCgeV0+hbA8hMs4=
	74	+	golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
	75	+	golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
	76	+	golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
	77	+	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
	78	+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
	79	+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
	80	+	gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
	81	+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
	82	+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
	83	+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
	84	+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
	85	+	rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
31	86

■ ■ ■ ■ ■ ■

man/dnstt-client.1

1	+	.\" https://man.openbsd.org/mdoc.7
2	+	.Dd 2020-08-30
3	+	.Dt DNSTT-CLIENT 1
4	+	.Os
5	+
6	+
7	+	.Sh NAME
8	+
9	+	.Nm dnstt-client
10	+	.Nd DNS tunnel client
11	+
12	+
13	+	.Sh SYNOPSIS
14	+
15	+	.Nm
16	+	.Op Fl doh Ar URL \| Fl dot Ar HOST : Ns Ar PORT \| Fl udp Ar HOST : Ns Ar PORT
17	+	.Op Fl pubkey Ar HEX \| Fl pubkey-file Ar FILENAME
18	+	.Ar DOMAIN
19	+	.Ar LOCALADDR : Ns Ar LOCALPORT
20	+
21	+
22	+	.Sh DESCRIPTION
23	+
24	+	.Nm
25	+	is the client portion of a DNS tunnel.
26	+	It receives TCP connections at
27	+	.Ar LOCALADDR : Ns Ar LOCALPORT
28	+	and forwards them,
29	+	encoded as a sequence of DNS messages
30	+	and via a recursive resolver,
31	+	to an instance of
32	+	.Xr dnstt-server 1
33	+	running as the authoritative name server for
34	+	.Ar DOMAIN .
35	+	The DNS messages may be carried over
36	+	DNS over HTTPS,
37	+	DNS over TLS,
38	+	or classical DNS over UDP.
39	+
40	+	.Pp
41	+	You must use exactly one of the
42	+	.Fl doh ,
43	+	.Fl dot ,
44	+	or
45	+	.Fl udp
46	+	options,
47	+	to specify what form of DNS to use:
48	+
49	+	.Bl -tag
50	+
51	+	.It Fl doh Ar URL
52	+	Use DNS over HTTPS.
53	+	.Ar URL
54	+	is the URL of the DNS over HTTPS resolver,
55	+	including the
56	+	.Ql /dns-query
57	+	path if used by the resolver.
58	+
59	+	.Pp
60	+	See
61	+	.Lk https://github.com/curl/curl/wiki/DNS-over-HTTPS#publicly-available-servers
62	+	for a list of public DNS over HTTPS resolvers.
63	+
64	+	.It Fl dot Ar HOST : Ns Ar PORT
65	+	Use DNS over TLS.
66	+	.Ar HOST
67	+	and
68	+	.Ar PORT
69	+	are the TCP address of the DNS over TLS resolver.
70	+	.Ar PORT
71	+	is normally 853.
72	+
73	+	.Pp
74	+	See
75	+	.Lk https://dnsprivacy.org/wiki/display/DP/DNS+Privacy+Public+Resolvers#DNSPrivacyPublicResolvers-DNS-over-TLS%28DoT%29
76	+	for a list of public DNS over TLS resolvers.
77	+
78	+	.It Fl udp Ar HOST : Ns Ar PORT
79	+	Use DNS over UDP.
80	+	.Ar HOST
81	+	and
82	+	.Ar PORT
83	+	are the UDP address of the DNS resolver.
84	+	.Ar PORT
85	+	is normally 53.
86	+
87	+	With
88	+	.Fl udp ,
89	+	you have the option of communicating directly with an instance of
90	+	.Xr dnstt-server 1 ,
91	+	without going through a recursive resolver.
92	+	That is,
93	+	.Ar HOST : Ns Ar PORT
94	+	may point directly at the authoritative name server for
95	+	.Ar DOMAIN ,
96	+	where
97	+	.Xr dnstt-server 1
98	+	is running.
99	+
100	+	.El
101	+
102	+	.Pp
103	+	In addition, you must use one of the
104	+	.Fl pubkey
105	+	or
106	+	.Fl pubkey-file
107	+	options to specify the public key used
108	+	for authenticating the server and encrypting the channel.
109	+	The public key should have been generated by
110	+	.Ql dnstt-server -gen-key .
111	+	.Xr dnstt-server 1
112	+	prints its public key at the beginning of its log output.
113	+
114	+	.Bl -tag
115	+
116	+	.It Fl pubkey Ar HEX
117	+	.Ar HEX
118	+	is a string of 64 hexadecimal digits.
119	+
120	+	.It Fl pubkey-file Ar FILENAME
121	+	.Ar FILENAME
122	+	is the name of a file containing
123	+	64 hexadecimal digits and an
124	+	optional training newline character.
125	+
126	+	.El
127	+
128	+	.Sh EXAMPLES
129	+
130	+	Tunnel through the DNS over HTTPS resolver at
131	+	.Cm https://resolver.example/dns-query
132	+	to the authoritative name server for
133	+	.Cm t.example.com .
134	+	Listen locally at
135	+	.Cm 127.0.0.1:7000
136	+	for connections to forward through the tunnel.
137	+	Use the server public key stored in the file
138	+	.Cm server.pub .
139	+
140	+	.Bd -literal -offset indent
141	+	dnstt-client -doh https://resolver.example/dns-query -pubkey-file server.pub t.example.com 127.0.0.1:7000
142	+	.Ed
143	+
144	+	.Pp
145	+	Tunnel through the DNS over TLS resolver at
146	+	.Cm resolver.example:853
147	+	to the authoritative name server for
148	+	.Cm t.example.com .
149	+	Listen locally at
150	+	.Cm 127.0.0.1:7000
151	+	for connections to forward through the tunnel.
152	+	Use the given hex string as the server public key.
153	+
154	+	.Bd -literal -offset indent
155	+	dnstt-client -dot resolver.example:853 -pubkey 14ca15f53660e248d289d9302f992c4bee518f2361d6343dafa7b417b5a3d752 t.example.com 127.0.0.1:7000
156	+	.Ed
157	+
158	+
159	+	.Sh DIAGNOSTICS
160	+
161	+	.Nm
162	+	writes running logs to standard error.
163	+
164	+	At startup,
165	+	.Nm
166	+	logs the amount of useful payload capacity that can be stored
167	+	in each DNS query, after accounting for the overhead of encoding.
168	+	This number will vary depending on the length of
169	+	.Ar DOMAIN .
170	+
171	+	.Dl effective MTU 128
172	+
173	+
174	+	.Sh BUGS
175	+
176	+	.Nm
177	+	has a distinctive TLS fingerprint
178	+	and is probably easy to block on that basis.
179	+
180	+
181	+	.Sh SECURITY CONSIDERATIONS
182	+
183	+	The
184	+	.Fl udp
185	+	option is not covert,
186	+	and is intended for debugging and special configurations.
187	+	Only the
188	+	.Fl doh
189	+	and
190	+	.Fl dot
191	+	modes provide protection against detection of the tunnel,
192	+	because they encrypt DNS messages between
193	+	.Nm
194	+	and the recursive resolver.
195	+	The
196	+	.Fl udp
197	+	mode sends plaintext DNS messages,
198	+	which reveal the use of a DNS tunnel by their special format.
199	+
200	+	Even with
201	+	.Fl doh
202	+	or
203	+	.Fl dot ,
204	+	it may be possible for an observer to infer
205	+	the use of a tunnel
206	+	by traffic metadata features such as
207	+	traffic volume and timing.
208	+	The recursive resolver can see the plaintext of DNS messages
209	+	and is always in a position to easily detect the use of a tunnel.
210	+
211	+	But even if the use of a tunnel is detected, the
212	+	.Em contents
213	+	of the tunnel remain encrypted and authenticated.
214	+	The end-to-end encryption and authentication of the tunnel is a separate layer,
215	+	independent of the encryption
216	+	provided by DNS over HTTPS or DNS over TLS.
217	+
218	+
219	+	.Sh SEE ALSO
220	+
221	+	.Xr dnstt-server 1
222	+
223	+	.Lk https://www.bamsoftware.com/software/dnstt/
224	+
225	+
226	+	.Sh AUTHORS
227	+
228	+	.An David Fifield Aq Mt [email protected]
229	+

■ ■ ■ ■ ■ ■

man/dnstt-server.1

1	+	.\" https://man.openbsd.org/mdoc.7
2	+	.Dd 2020-08-30
3	+	.Dt DNSTT-SERVER 1
4	+	.Os
5	+
6	+
7	+	.Sh NAME
8	+
9	+	.Nm dnstt-server
10	+	.Nd DNS tunnel server
11	+
12	+
13	+	.Sh SYNOPSIS
14	+
15	+	.Nm
16	+	.Fl gen-key
17	+	.Op Fl privkey-file Ar FILENAME
18	+	.Op Fl pubkey-file Ar FILENAME
19	+
20	+	.Nm
21	+	.Fl udp Ar ADDR : Ns Ar PORT
22	+	.Op Fl privkey Ar HEX \| Fl privkey-file Ar FILENAME
23	+	.Op Fl mtu Ar MTU
24	+	.Ar DOMAIN
25	+	.Ar UPSTREAMADDR : Ns Ar UPSTREAMPORT
26	+
27	+
28	+	.Sh DESCRIPTION
29	+
30	+	.Nm
31	+	is the server portion of a DNS tunnel.
32	+	It receives DNS over UDP messages at
33	+	.Ar ADDR : Ns Ar PORT ,
34	+	decodes the streams they contain,
35	+	and forwards the streams as TCP connections to
36	+	.Ar UPSTREAMADDR : Ns Ar UPSTREAMPORT .
37	+	.Nm acts as the authoritative name server for
38	+	.Ar DOMAIN
39	+	and communicates with an instance of
40	+	.Xr dnstt-client 1
41	+	via a recursive resolver.
42	+
43	+	.Ss GENERATING A SERVER KEYPAIR
44	+
45	+	The tunnel client
46	+	encrypts and authenticates the tunneled connection
47	+	using the server's public key.
48	+	To generate a server keypair, use the
49	+	.Fl gen-key
50	+	option.
51	+	Use the
52	+	.Fl privkey-file
53	+	and
54	+	.Fl pubkey-file
55	+	options to save the generated private key,
56	+	public key, or both,
57	+	to a file.
58	+
59	+	.Bl -tag
60	+
61	+	.It Fl gen-key
62	+	Generate a server keypair.
63	+
64	+	.It Fl privkey-file Ar FILENAME
65	+	With
66	+	.Fl gen-key ,
67	+	save the generated private key to
68	+	.Ar FILENAME .
69	+
70	+	.It Fl pubkey-file Ar FILENAME
71	+	With
72	+	.Fl gen-key ,
73	+	save the generated public key to
74	+	.Ar FILENAME .
75	+
76	+	.El
77	+
78	+	.Pp
79	+	On the server, you only need to store the private key, because
80	+	.Nm
81	+	can derive the public key from the private key.
82	+	The client only needs to have the server's public key
83	+	and should not know the servers private key.
84	+
85	+	.Ss RUNNING THE SERVER
86	+
87	+	The required
88	+	.Fl udp
89	+	option specifies the UDP address on which
90	+	.Nm
91	+	listens for incoming DNS messages.
92	+
93	+	.Bl -tag
94	+	.It Fl udp Ar ADDR : Ns Ar PORT
95	+	Accept DNS messages at the given address.
96	+	.Ar PORT
97	+	must typically be 53
98	+	when operating with a recursive intermediate resolver,
99	+	unless you have made some other provision for forwarding
100	+	port 53 to
101	+	.Ar PORT .
102	+
103	+	.El
104	+
105	+	.Pp
106	+	Specify the server's persistent keypair using the
107	+	.Fl privkey
108	+	or
109	+	.Fl privkey-file
110	+	options.
111	+	If you do not use one of these options,
112	+	.Nm
113	+	generates a temporary keypair
114	+	and logs the public key to standard error.
115	+
116	+	.Bl -tag
117	+
118	+	.It Fl privkey Ar HEX
119	+	.Ar HEX
120	+	is a string of 64 hexadecimal digits.
121	+
122	+	.It Fl privkey-file Ar FILENAME
123	+	.Ar FILENAME
124	+	is the name of a file containing
125	+	64 hexadecimal digits and an
126	+	optional training newline character.
127	+
128	+	.El
129	+
130	+	.Pp
131	+	In some situations, you may have to use the
132	+	.Fl mtu
133	+	option to control the maximum UDP payload size.
134	+
135	+	.Bl -tag
136	+
137	+	.It Fl mtu Ar MTU
138	+	Never send UDP payloads larger than
139	+	.Ar MTU
140	+	bytes.
141	+	The default
142	+	.Ar MTU
143	+	is 1232, but some recursive resolver only support a maximum of 512.
144	+	You will know you need to use the
145	+	.Fl mtu
146	+	option when you see messages like this on standard error:
147	+	.Dl FORMERR: requester payload size 512 is too small (minimum 1232)
148	+
149	+	.El
150	+
151	+
152	+	.Sh EXAMPLES
153	+
154	+	Generate a keypair.
155	+	Save the private key to the file
156	+	.Cm server.key
157	+	and the public key to
158	+	.Cm server.pub .
159	+	Next, you would typically copy
160	+	.Pa server.pub
161	+	to the client.
162	+
163	+	.Bd -literal -offset indent
164	+	dnstt-server -gen-key -privkey-file server.key -pubkey-file server.pub
165	+	.Ed
166	+
167	+	.Pp
168	+	Accept DNS messages at the UDP address
169	+	.Cm 0.0.0.0:53 ,
170	+	decode the streams contained therein,
171	+	and forward the streams as TCP connections to
172	+	.Cm 127.0.0.1:8000 .
173	+	Read the private key from the file
174	+	.Cm server.key
175	+	and derive the public key from it.
176	+	The server should be configured to be
177	+	the authoritative name server for the domain
178	+	.Cm t.example.com .
179	+
180	+	.Bd -literal -offset indent
181	+	dnstt-server -udp 127.0.0.1:53 -privkey-file server.key t.example.com 127.0.0.1:8000
182	+	.Ed
183	+
184	+
185	+	.Sh DIAGNOSTICS
186	+
187	+	.Nm
188	+	writes running logs to standard error.
189	+
190	+	At startup,
191	+	.Nm
192	+	logs its public key.
193	+	This string can be used with the
194	+	.Fl -pubkey
195	+	option in
196	+	.Xr dnstt-client 1 .
197	+
198	+	.Dl pubkey 14ca15f53660e248d289d9302f992c4bee518f2361d6343dafa7b417b5a3d752
199	+
200	+	.Pp
201	+	At startup,
202	+	.Nm
203	+	logs the amount of useful payload capacity that can be stored
204	+	in each DNS response, after accounting for the overhead of encoding.
205	+	This number will vary depending on the length of
206	+	.Ar DOMAIN
207	+	and the value of
208	+	.Ar MTU .
209	+
210	+	.Dl effective MTU 932
211	+
212	+
213	+	.Pp
214	+	If the recursive resolver's stated maximum UDP payload size
215	+	is smaller than
216	+	.Ar MTU ,
217	+	.Nm
218	+	will log a message like this,
219	+	which tells you that you need to use the
220	+	.Fl mtu
221	+	option.
222	+
223	+	.Dl FORMERR: requester payload size 512 is too small (minimum 1232)
224	+
225	+
226	+	.Sh SEE ALSO
227	+
228	+	.Xr dnstt-client 1
229	+
230	+	.Lk https://www.bamsoftware.com/software/dnstt/
231	+
232	+
233	+	.Sh AUTHORS
234	+
235	+	.An David Fifield Aq Mt [email protected]
236	+

■ ■ ■ ■ ■ ■

noise/noise.go

		skipped 110 lines
111	111		if n > 4096 {
112	112		n = 4096
113	113		}
114		-	err := writeMessage(s.ReadWriteCloser, s.sendCipher.Encrypt(nil, nil, p[:n]))
	114	+	msg, err := s.sendCipher.Encrypt(nil, nil, p[:n])
	115	+	if err != nil {
	116	+	return total, err
	117	+	}
	118	+	err = writeMessage(s.ReadWriteCloser, msg)
115	119		if err != nil {
116	120		return total, err
117	121		}
		skipped 159 lines
277	281		return key, err
278	282		}
279	283
280		-	// DecodeKey decodes a hex-encoded private or public key.
	284	+	// EncodeKey encodes a hex-encoded private or public key.
281	285		func EncodeKey(key []byte) string {
282	286		return hex.EncodeToString(key)
283	287		}
		skipped 1 lines

Merge tag 'v0.20210424.0' into plugin